Answer:
That something is called having a high viscosity.
Explanation:
The measure expressing a "resistance to flow" is called viscosity. Viscosity relates to internal friction forces in a fluid causing it to flow with more or less difficulty. Highly viscous stuff is perceived "thick" or "sticky."
Answer:
162.78 m/s is the most probable speed of a helium atom.
Explanation:
The most probable speed:

= Boltzmann’s constant =
T = temperature of the gas
m = mass of the gas particle.
Given, m = 
T = 6.4 K
Substituting all the given values :


162.78 m/s is the most probable speed of a helium atom.
Answer:
The expresion for the flux through the disk is:
Ф = E·πR^2·cos(Θ).
Explanation:
Let's sat the electric field has direction e and the normal to the disk has direction n (bold means vector quantities). So we have:
E=E·e (where E is the magnitud of the electric flied)
A=A·n
The flux for an uniform electric field and a flat surface is:
Ф=E×A
⇒ Ф = E·A·e×n = E·A·cos(angle(e,n)) = E·A·cos(Θ)
Since in this case the area is for a disk of radius R, 
So, Ф = E·πR^2·cos(Θ)
Answer:
12N to the right.
Explanation:
There is a force of 12N upwards and a force of 12N downwards: these cancel out.
Assign a negative value to forces towards the left, and a positive value to the forces towards the right: -3N and +15N
Combine them: -3N+15N = 12N
The net force has a magnitude of 12N, and since our answer was positive, it acts towards the right.